1. Field of the Invention
This invention relates generally to apparatus and methods for manufacturing optical and photonic devices by employing the micro-opto-electro-mechanical system (MOEMS) technologies. More particularly, this invention is related to configuration and method of manufacturing optical devices by applying MOEMS technologies with defined sacrifical region by ion-implantation.
2. Description of the Related Art
Recent development of the is still faced with a technical limitation that the optical chamber etched on a sacrificial layer is often etched with irregularities and undercut when dry or wet etching processes are applied. Current manufacturing processes apply a surface micro-machining technique that uses oxide or phosphorous doped silicate glass (PSG) as the sacrificial etch materials Meanwhile, the sacrificial etch layer composed of the PSG material is also implemented as structural elements in the optical device formed as the chamber poles. A typical example is the optical modulators implemented with the configuration of a mechanical anti-reflection (MAR) switch. The manufacture irregularities produced by applying the dry or wet etching processes and using the conventional sacrificial etch materials adversely affect the production yields and the switching/attenuation performance and also the reliability of the devices. The next generation broadband optical communication system requires significant scale-down of size and reduction in production costs from current standards based on technology of devices by mechanically assembling optical components. Recent development of silicon based optical single switch modulator and integrated multiple-channel attenuation/switching modules provides first step in a pathway of achieving improvement to provide optical devices suitable for next generation system applications. However, the irregularities of the supporting structure for a free standing membrane caused by the ineffectiveness of the stop etching configuration due to sacrificial layer undercut in the membrane forming processes often limit the applications and production yields when such technologies are applied.
Therefore, a still need exists in the art in the field of the optical signal transmission systems to provide a configuration and method of manufacture to overcome such difficulties and limitations. It is desirable that such method can provide simplified manufacturing processes such that cost reduction and production yields together with the product reliability can be improved. In addition, it is further desired that more process control can be provided for more precisely controlling the manufacturing processes to produce optical devices with size and dimensions with better controlled accuracy.
It is therefore an object of the present invention to provide new and improved configuration and methods for manufacturing optical devices to substantially eliminate the etching irregularities caused by undercuts such that the problems and difficulties as encountered in the prior art may be resolved.
Specifically, it is the object of this invention to provide new and improved manufacture methods and configurations to form well-defined regions on sacrificial layer by applying different types of ion-implantation to form etch-enhanced and resistant regions. Free-standing membrane can be formed by etching through an etching window on top of etching enhancement region surrounded by etch-resistant region such that chamber can be formed by removing the etch-enhancement regions with precisely controllable chamber formation processes. The optical chambers are formed with well-defined wall where the undercut irregularities can be substantially removed.
Briefly, in a preferred embodiment, this invention discloses an electro-optical device support on a substrate. The electro-optical device includes a sacrificial layer disposed on the substrate having a chamber-wall region surrounding and defining an optical chamber. The electro-optical device further includes a membrane layer disposed on top of the sacrificial layer having a chamber-removal opening surrounding and defining an electric tunable membrane for transmitting an optical signal therethrough. The electrically tunable membrane disposed on top of the optical chamber surrounded by the chamber wall regions. The chamber-wall region is doped with ion-dopants for maintaining the chamber-wall region for removal-resistance under a chamber-forming process performed through the chamber-removal opening. In a preferred embodiment, the chamber-wall region is a doped silicon dioxide region with carbon or nitrogen. In another preferred embodiment, the chamber-wall region is a nitrogen ion-doped SiNxOy region. In another preferred embodiment, the optical chamber is an etched chamber formed by etching through the chamber removal opening for etching off an etch-enhanced region surrounded by an etch-resistant region constituting the chamber wall.
These and other objects and advantages of the present invention will no doubt become obvious to those of ordinary skill in the art after having read the following detailed description of the preferred embodiment which is illustrated in the various drawing figures.